Spin-density-functional theory: some open problems and application to inhomogeneous Heisenberg models

Spin-density-functional theory (SDFT) is the most widely implemented and applied formulation of density-functional theory. However, it is still finding novel applications, and occasionally encounters unexpected problems. In this paper we first briefly describe a few of the latter, related to issues such as nonuniqueness, noncollinearity, and currents. In the main part we then turn to an example of the former, namely SDFT for the Heisenberg model. It is shown that time-honored concepts of Coulomb DFT, such as the local-density approximation, can be applied to this (and other) model Hamiltonians, too, once the concept of 'density' has been suitably reinterpreted. Local-density-type approximations for the inhomogeneous Heisenberg model are constructed. Numerical applications to finite-size and impurity systems demonstrate that DFT is a computationally efficient and reasonably accurate alternative to conventional methods of statistical mechanics for the Heisenberg model.Comment: 15 pages, 1 figure, 1 tabl

Many-electron tunneling in atoms

A theoretical derivation is given for the formula describing N-electron ionization of atom by a dc field and laser radiation in tunneling regime. Numerical examples are presented for noble gases atoms.Comment: 11 pages, 1 EPS figure, submitted to JETP (Jan 99

A quasi classical approach to electron impact ionization

A quasi classical approximation to quantum mechanical scattering in the Moeller formalism is developed. While keeping the numerical advantage of a standard Classical--Trajectory--Monte--Carlo calculation, our approach is no longer restricted to use stationary initial distributions. This allows one to improve the results by using better suited initial phase space distributions than the microcanonical one and to gain insight into the collision mechanism by studying the influence of different initial distributions on the cross section. A comprehensive account of results for single, double and triple differential cross sections for atomic hydrogen will be given, in comparison with experiment and other theories.Comment: 21 pages, 10 figures, submitted to J Phys

VACCELERATE Site Network: Real-time definition of clinical study capacity in Europe

Background: The inconsistent European vaccine trial landscape rendered the continent of limited interest for vaccine developers. The VACCELERATE consortium created a network of capable clinical trial sites throughout Europe. VACCELERATE identifies and provides access to state-of-the-art vaccine trial sites to accelerate clinical development of vaccines. Methods: Login details for the VACCELERATE Site Network (vaccelerate.eu/site-network/) questionnaire can be obtained after sending an email to. Interested sites provide basic information, such as contact details, affiliation with infectious disease networks, main area of expertise, previous vaccine trial experience, site infrastructure and preferred vaccine trial settings. In addition, sites can recommend other clinical researchers for registration in the network. If directly requested by a sponsor or sponsor representative, the VACCELERATE Site Network pre-selects vaccine trial sites and shares basic study characteristics provided by the sponsor. Interested sites provide feedback with short surveys and feasibility questionnaires developed by VACCELERATE and are connected with the sponsor to initiate the site selection process. Results: As of April 2023, 481 sites from 39 European countries have registered in the VACCELERATE Site Network. Of these, 137 (28.5 %) sites have previous experience conducting phase I trials, 259 (53.8 %) with phase II, 340 (70.7 %) with phase III, and 205 (42.6 %) with phase IV trials, respectively. Infectious diseases were reported as main area of expertise by 274 sites (57.0 %), followed by any kind of immunosuppression by 141 (29.3 %) sites. Numbers are super additive as sites may report clinical trial experience in several indications. Two hundred and thirty-one (47.0 %) sites have the expertise and capacity to enrol paediatric populations and 391 (79.6 %) adult populations. Since its launch in October 2020, the VACCELERATE Site Network has been used 21 times for academic and industry trials, mostly interventional studies, focusing on different pathogens such as fungi, monkeypox virus, Orthomyxoviridae/influenza viruses, SARS-CoV-2, or Streptococcus pneumoniae/pneumococcus. Conclusions: The VACCELERATE Site Network enables a constantly updated Europe-wide mapping of experienced clinical sites interested in executing vaccine trials. The network is already in use as a rapid-turnaround single contact point for the identification of vaccine trials sites in Europe.The VACCELERATE Site Network has received funding from the European Union’s Horizon 2020 research and innovation pro gramme (grant agreement No 101037867) and the German Federal Ministry of Education and Research (Bundesministerium für Bil dung und Forschung [BMBF]) (grant agreement No BMBF01KX2040).S

Predicting the next pandemic: VACCELERATE ranking of the World Health Organization's Blueprint for Action to Prevent Epidemics

Introduction: The World Health Organization (WHO)'s Research and Development (R&D) Blueprint for Action to Prevent Epidemics, a plan of action, highlighted several infectious diseases as crucial targets for prevention. These infections were selected based on a thorough assessment of factors such as transmissibility, infectivity, severity, and evolutionary potential. In line with this blueprint, the VACCELERATE Site Network approached infectious disease experts to rank the diseases listed in the WHO R&D Blueprint according to their perceived risk of triggering a pandemic. VACCELERATE is an EU-funded collaborative European network of clinical trial sites, established to respond to emerging pandemics and enhance vaccine development capabilities. Methods: Between February and June 2023, a survey was conducted using an online form to collect data from members of the VACCELERATE Site Network and infectious disease experts worldwide. Participants were asked to rank various pathogens based on their perceived risk of causing a pandemic, including those listed in the WHO R&D Blueprint and additional pathogens. Results: A total of 187 responses were obtained from infectious disease experts representing 57 countries, with Germany, Spain, and Italy providing the highest number of replies. Influenza viruses received the highest rankings among the pathogens, with 79 % of participants including them in their top rankings. Disease X, SARS-CoV-2, SARS-CoV, and Ebola virus were also ranked highly. Hantavirus, Lassa virus, Nipah virus, and henipavirus were among the bottom-ranked pathogens in terms of pandemic potential. Conclusion: Influenza, SARS-CoV, SARS-CoV-2, and Ebola virus were found to be the most concerning pathogens with pandemic potential, characterised by transmissibility through respiratory droplets and a reported history of epidemic or pandemic outbreaks

EQUAL Trichosporon Score 2022: an ECMM score to measure QUALity of the clinical management of invasive Trichosporon infections

Background Invasive infections due to Trichosporon spp. are life-threatening opportunistic fungal infections that require complex clinical management. Guidelines assist clinicians but can be challenging to comply with. Objectives To develop a scoring tool to facilitate and quantify adherence to current guideline recommendations for invasive trichosporonosis. Methods We reviewed the current guideline for managing rare yeast infections (ECMM, ISHAM and ASM). The most important recommendations for diagnosis, treatment and follow-up were assembled and weighted according to their strength of recommendation and level of evidence. Additional items considered highly relevant for clinical management were also included. Results The resulting EQUAL Trichosporon Score 2022 comprises 18 items, with a maximum score of 39 points. For diagnostics, seven or eight items, depending on whether organ involvement is present or not, apply, resulting in a maximum of 18 or 21 points. Recommendations on diagnostics include imaging, infectious diseases expert consultation, culture, microscopy, molecular techniques, histopathology, and susceptibility testing. For treatment, six recommendations with a maximum of ten points were identified, with two additional points for organ involvement and one point for second-line treatment in uncontrolled disease. Treatment recommendations include immediate initiation, source control, pharmacological treatment, therapeutic drug monitoring, treatment duration and surgical intervention. Follow-up comprises two items with five points maximum, covering follow-up blood cultures and imaging. Conclusions The EQUAL Trichosporon Score weighs and aggregates factors recommended for optimal management of Trichosporon infections. It provides a tool for antifungal stewardship as well as for measuring guideline adherence, but remains to be correlated with patient outcomes

EQUAL Trichosporon Score 2022

The EQUAL Trichosporon Score weights and aggregates factors for ideal management of invasive trichosporon infections. Scores reflect the strongest guideline recommendations. EQUAL Score Cards reflect the strongest recommendations from current guidelines. The Score Cards are a quick reference to measure guideline adherence and to support antifungal stewardship

EQUAL Trichosporon Score 2022

Der EQUAL Trichosporon Score gewichtet Faktoren für das ideale Management von invasiven Trichosporon-Infektionen. EQUAL Scores geben die stärksten Empfehlungen der aktuellen Leitlinien wieder und dienen der Quantifizierung der Leitlinienadhärenz sowie dem Antimicrobial Stewardship (AMS)

Trichosporon 2022

Trichosporon 2022 позволяет определить основные факторы для оптимального лечения инвазивного трихоспороноза. Метод отражает наиболее важные рекомендации современных руководств и позволяет количественно оценить приверженность этим рекомендациям и оптимизировать антифунгальную терапию